Emu XL-7 & MP-7 User's Group

Hi all,

I'm getting a rather nasty buzzing (like hum, but with more highs :-) 
in the phones output of my MP7. The strange thing is that its' 
loudness is unaffected by main volume, and it somewhat changes in 
character while I scroll through patterns (maybe this is caused by 
switching effect algorithms). I had hum in the main outs, which was 
cured by lifting the ground on power cord; this buzz, however, 
remains. Any ideas?

Have a nice day everybody!
Boris.